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Industrial filtration apparatus
INVENTIONSINFILTRATIONANDSEPARATION Abstracts of British Patents Industrial filtration apparatus
Air filter
In GB 2247186 George Clough describes an a p p a r a t u s for f i l t e r i n g treated or untreated sewage. A nozzle feeds the sewage into a long net sleeve, most of which is folded around the nozzle, while an end portion extends clear of the nozzle and is closed at one end. A spring-loaded ring grips the sleeve against the nozzle end, but allows further sleeve sections to be pulled off the nozzle into the working position, whenever the pressure drop across the sleeve rises enough. Rollers pull the sleeve forwards, in response to excess pressure being detected, and squeeze excess liquid from the solids. Alternatively the sleeve is closed at one end, and the internal pressure acts directly to pull the sleeve progressively off the nozzle. (2figures, 2500 words)
In GB 2248409 John Thompson describes an air filter w h i c h h as a transparent housing containing soda lime granules incorporating a colour indicator. The filter also has an activated carbon filter in two parts. In use, fumes of hydrocarbon are removed from air by the activated carbon filter, and carbon dioxide is removed from air by the soda lime granules. When the soda lime granules are exhausted they change colour; the colour change is readily seen through the transparent housing. (1 figure, 1000 words)
Counter electrode for electrochemical filter cleaning In GB 2247469 the UK Atomic Energy Authority describes a counter electrode, suitable for periodic application during ultrafiltration of a potential difference between an electrically conducting filter medium and a counter electrode (as anode). A gaseous product is generated at the filter, and cleans the filter to minimise corrosion. The electrode is low-chromium stainless steel, e.g. 9% chromium. A sintered stainless-steel fibre membrane with a 3 #m pore size on one surface and 10 #m on the other (used with the coarse surface facing the liquid to be filtered) can, with regular electrocleaning, provide as good a rejection of fines as ultrafiltration. (no figures, 2000 words)
Filter module In GB 2248408 Seitz-Filter-Werk/Seitz GmbH describes a filter module for crossflow filtration. An annular sealing ring encloses a stack of double-sided, flat, hollow filter units separated by open mesh spacers. Each unit is sealed around its periphery, part of which is embedded in the annular sealing ring t h i c k n e s s w h e r e its i n t e r i o r space opens into at least one axially extending filtrate channel. At least one other part of the periphery is spaced from the annular sealing ring interior face, to define channels by which fluid is fed to and removed from the units' upstream faces. The fluid flows from one channel to another within the spacer planes. In use, several modules are stacked within a tubular casing. Suitable end plates enable module stacks to operate in parallel. (17figures, 11,000 words) 126
Liquid separation In GB 2248788 Smir Abed Issa Albasri describes the separation of two liquids by gravity in a two-part container, the parts of which are connected by a narrow flexible portion. An interface is moved into the narrow portion, by draining off liquid via a tap. The narrow portion is constricted to isolate the two parts of the container, and the liquids are removed separately. In one version, the portion is constricted by twisting the upper part relative to the lower. In other versions, a narrow neck connecting the two parts is closed by one or two clamps. Liquid may be drained from t h e u p p e r p a r t v i a a floatsupported overflow. The interface position may be monitored by an EM radiation system. (4 figures, 2500 words)
Porous ceramic exhaust filter In GB 2248833 The Duriron Comany describes a filtering element for use in trapping particulates from diesel exh a u s t gas. It consists of a porous refractory ceramic body of predominantly open-cell porosity prepared by firing an a l u m i n o s i l i c a t e hydrogelbonded porous ceramic composition. On the filter body's inlet or outlet surface there is an integral thin porous ceramic membrane layer with pores of an average diameter less than the pores in the body and at the other surface. The filter uses mouldable/extrudable compositions which enable a variety of shapes to be provided, methods for rendering those shapes more refractory and resistant to t h er m al shock on firing, and methods for providing thin porous ceramic membrane layers on the fired article to enhance its filtering ability. (no figures, 7700 words)
fountain pump. It is formed by a casing which completely encloses the pump assembly. The pump delivery or pressure line passes through the casing. This arrangement increases the intake surface area of the filter to an extent that effectively prevents clogging. In addition, the filter protects the pump assembly from mechanical damage, as well as serving as packing for the pump assembly. (4 figures, 2000 words)
Electrostatic/centrifugal liquid dispersion separation In GB 2249741 t h e U n i v e r s i t y of Bradford describes the separation of liquid dispersions. Components of a liquid-liquid dispersion or emulsion are separated by simultaneously applying an electric field and a centrifugal force to set up a bulk interface at right angles to the direction of the electric field and centrifugal force. The bulk interface is located within the electric field, between the dispersion or emulsion and one separated component. The combined effects of the electric field and centrifugal force break the liquid emulsion, preventing the formation of a sponge layer at the interface. In one version an aqueous emulsion is fed into a rotating cylinder via plastic tubes and a distributor. Water is removed from the cylinder periphery, and the organic component from adjacent tubes. An electrolyte is provided between the tubes. A m e c h a n i c a l c e n t r i f u g e or hydrocyclone may be used. Brine/oil and w at er / p et r o l eu m dispersions can be treated. (7figures, 4000 words)
Liquid effluent filter system In GB 2249490 Peter Wraith describes a liquid effluent filter system. The vessel has an overflow weir, and a filter which liquid must flow through before reaching the weir. A flexible isolating flap is anchored to the internal vessel wall. A chamber can be inflated to elevate the flap so that it rises against the filter's inner side and, being impermeable, isolates t h e l a t t e r from the vessel interior. The zone around the filter is t h e n e m p t i e d and t h e filter backwashed, with used backwash liquid passing through the normally closed outlet. The filter may comprise buoyant polystyrene beads in a mesh sleeve or sack supported by a rigid frame. Filter and flap may form separate sections spaced along the weir, so that different filter sections may be backwashed in turn. (2figures, 2000words) []
Pump intake filter/casing In GB 2249136 Grundfos International describes the intake filter for a submersible pump, and in particular for a March/April 1993
Filtration & Separation
Air filter
In GB 2247186 George Clough describes an a p p a r a t u s for f i l t e r i n g treated or untreated sewage. A nozzle feeds the sewage into a long net sleeve, most of which is folded around the nozzle, while an end portion extends clear of the nozzle and is closed at one end. A spring-loaded ring grips the sleeve against the nozzle end, but allows further sleeve sections to be pulled off the nozzle into the working position, whenever the pressure drop across the sleeve rises enough. Rollers pull the sleeve forwards, in response to excess pressure being detected, and squeeze excess liquid from the solids. Alternatively the sleeve is closed at one end, and the internal pressure acts directly to pull the sleeve progressively off the nozzle. (2figures, 2500 words)
In GB 2248409 John Thompson describes an air filter w h i c h h as a transparent housing containing soda lime granules incorporating a colour indicator. The filter also has an activated carbon filter in two parts. In use, fumes of hydrocarbon are removed from air by the activated carbon filter, and carbon dioxide is removed from air by the soda lime granules. When the soda lime granules are exhausted they change colour; the colour change is readily seen through the transparent housing. (1 figure, 1000 words)
Counter electrode for electrochemical filter cleaning In GB 2247469 the UK Atomic Energy Authority describes a counter electrode, suitable for periodic application during ultrafiltration of a potential difference between an electrically conducting filter medium and a counter electrode (as anode). A gaseous product is generated at the filter, and cleans the filter to minimise corrosion. The electrode is low-chromium stainless steel, e.g. 9% chromium. A sintered stainless-steel fibre membrane with a 3 #m pore size on one surface and 10 #m on the other (used with the coarse surface facing the liquid to be filtered) can, with regular electrocleaning, provide as good a rejection of fines as ultrafiltration. (no figures, 2000 words)
Filter module In GB 2248408 Seitz-Filter-Werk/Seitz GmbH describes a filter module for crossflow filtration. An annular sealing ring encloses a stack of double-sided, flat, hollow filter units separated by open mesh spacers. Each unit is sealed around its periphery, part of which is embedded in the annular sealing ring t h i c k n e s s w h e r e its i n t e r i o r space opens into at least one axially extending filtrate channel. At least one other part of the periphery is spaced from the annular sealing ring interior face, to define channels by which fluid is fed to and removed from the units' upstream faces. The fluid flows from one channel to another within the spacer planes. In use, several modules are stacked within a tubular casing. Suitable end plates enable module stacks to operate in parallel. (17figures, 11,000 words) 126
Liquid separation In GB 2248788 Smir Abed Issa Albasri describes the separation of two liquids by gravity in a two-part container, the parts of which are connected by a narrow flexible portion. An interface is moved into the narrow portion, by draining off liquid via a tap. The narrow portion is constricted to isolate the two parts of the container, and the liquids are removed separately. In one version, the portion is constricted by twisting the upper part relative to the lower. In other versions, a narrow neck connecting the two parts is closed by one or two clamps. Liquid may be drained from t h e u p p e r p a r t v i a a floatsupported overflow. The interface position may be monitored by an EM radiation system. (4 figures, 2500 words)
Porous ceramic exhaust filter In GB 2248833 The Duriron Comany describes a filtering element for use in trapping particulates from diesel exh a u s t gas. It consists of a porous refractory ceramic body of predominantly open-cell porosity prepared by firing an a l u m i n o s i l i c a t e hydrogelbonded porous ceramic composition. On the filter body's inlet or outlet surface there is an integral thin porous ceramic membrane layer with pores of an average diameter less than the pores in the body and at the other surface. The filter uses mouldable/extrudable compositions which enable a variety of shapes to be provided, methods for rendering those shapes more refractory and resistant to t h er m al shock on firing, and methods for providing thin porous ceramic membrane layers on the fired article to enhance its filtering ability. (no figures, 7700 words)
fountain pump. It is formed by a casing which completely encloses the pump assembly. The pump delivery or pressure line passes through the casing. This arrangement increases the intake surface area of the filter to an extent that effectively prevents clogging. In addition, the filter protects the pump assembly from mechanical damage, as well as serving as packing for the pump assembly. (4 figures, 2000 words)
Electrostatic/centrifugal liquid dispersion separation In GB 2249741 t h e U n i v e r s i t y of Bradford describes the separation of liquid dispersions. Components of a liquid-liquid dispersion or emulsion are separated by simultaneously applying an electric field and a centrifugal force to set up a bulk interface at right angles to the direction of the electric field and centrifugal force. The bulk interface is located within the electric field, between the dispersion or emulsion and one separated component. The combined effects of the electric field and centrifugal force break the liquid emulsion, preventing the formation of a sponge layer at the interface. In one version an aqueous emulsion is fed into a rotating cylinder via plastic tubes and a distributor. Water is removed from the cylinder periphery, and the organic component from adjacent tubes. An electrolyte is provided between the tubes. A m e c h a n i c a l c e n t r i f u g e or hydrocyclone may be used. Brine/oil and w at er / p et r o l eu m dispersions can be treated. (7figures, 4000 words)
Liquid effluent filter system In GB 2249490 Peter Wraith describes a liquid effluent filter system. The vessel has an overflow weir, and a filter which liquid must flow through before reaching the weir. A flexible isolating flap is anchored to the internal vessel wall. A chamber can be inflated to elevate the flap so that it rises against the filter's inner side and, being impermeable, isolates t h e l a t t e r from the vessel interior. The zone around the filter is t h e n e m p t i e d and t h e filter backwashed, with used backwash liquid passing through the normally closed outlet. The filter may comprise buoyant polystyrene beads in a mesh sleeve or sack supported by a rigid frame. Filter and flap may form separate sections spaced along the weir, so that different filter sections may be backwashed in turn. (2figures, 2000words) []
Pump intake filter/casing In GB 2249136 Grundfos International describes the intake filter for a submersible pump, and in particular for a March/April 1993
Filtration & Separation